The present patent application is a Divisional of application Ser. No. 10/970,348, filed Oct. 20, 2004 now U.S. Pat. No. 7,327,771.
This application claims the priority of Korean Patent Applications No. 2003-73448, filed on Oct. 21, 2003 and No. 2004-72041, filed on Sep. 9, 2004, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein in their entirety by reference.
1. Field of the Invention
The present invention relates to a wavelength division multiplexing passive optical network (WDM-PON) system, and more particularly, to a WDM-PON with an optical wavelength alignment function for maintaining optical communication links regardless of an ambient temperature change.
2. Description of the Related Art
The variation of optical characteristics of modules included in a WDM-PON caused by a temperature change must be essentially considered in the WDM-PON.
In particular, since optical devices in a subscriber premises are exposed to the variance of ambient temperature in a subscribers network and the ambient temperature is different according to places in which the optical devices are installed, if this environment is not considered properly, optical communication quality cannot be satisfied. Therefore, a method of cost-effective solution with which a good quality of optical communications can be maintained regardless of the variance of ambient temperature in a WDM-PON system has been suggested.
That is, when a conventional WDM-PON system is applied to an actual environment, a WDM-PON system maintaining stable optical communication channels regardless of the variance of ambient temperature is required. Accordingly, a structure of stable and cost-effective optical communication links is required.